Synergetic Effect of Ultrasound Irradiation in the COD Removal and Degradation of L-Ascorbic Acid in Aqueous Solution by Aerobic Treatment

Abstract

The ultrasound irradiation and simultaneous oxygen bubbling into the L-ascorbic acid aqueous solution has been studied in order to establish a cost-effective oxidation process for wastewater treatment. The application of ultrasound considerably increases the decomposition rate, while the relative chemical oxygen demand (COD) value is essentially unchanged. The influence of various process parameters, such as temperature and oxygen flow rate, has been studied. Moreover, we have carried out preliminary experiments on the influence of the addition of metal oxide particles, i.e. SiO 2 and TiO 2 . The effects of particles on the degradation of AH 2 and the COD compounds are discussed.